Also, 3,000 people die every month on U.S. roads, your medicine analogy is wrong because there is much harm from the current system.
What can happen is if suddenly there's a race to market that throws process off the rails or a risk factor that was dismissed because of particulars of the culture that is producing the vehicles. That's where an outside inspector and premarket approval really helps.
Assume self-driving cars exist at some point. Assume they reduce fatalities by 90 percent. Ignore injuries. Now "only" 3,000 people are being killed by autonomous vehicles because "Hey, software isn't perfect and stuff happens." How many consumer products today kill that many people a year and the public is basically OK with it?
I'm not saying that the companies shouldn't make reasonable payments as a cost of doing business but if Ford manufacturing defects today were to kill 1,000 people a year they'd be sued out of existence.